A semiconductor manufacturing process generally includes a brushing process as a method to remove particles on a surface of a wafer. In the brushing process, a brush is moved to a position where the wafer is disposed and then the brush is rotated. Then, deionized water (DI water) and chemical diluent are dispersed in order to remove particles. Before the brush is driven to move to the position where the wafer is disposed, the brush is rotated constantly at a brush origin state, that is, a home position state.
A back surface of the wafer is required to be clean in order to clean and to process a front surface of the wafer without flaws. Substances attached to the back surface of the wafer are removed during processing and contaminate the front surface of the wafer.
When proceeding with a lithography process to realize an ultra-fine circuit, the substances of the back surface of a wafer causes a deformation of the wafer and being out of focus locally, so a desired circuit pattern is unable to be obtained. Therefore, the substances of the back surface of the wafer are required to be removed.
Conventionally, a process for removing the substances of the back surface of the wafer in a semiconductor manufacturing process is the only process cleaning with soft sponges. In such process, only particles combined with weak physical force are removed without polishing, so particles strongly combined with the back surface of the wafer are not removed, thereby causing process defects.
Therefore, in an effort to solve such problems, Korean Patent Application Publication No. 10-2008-0109181 proposed a device for cleaning wafer face of semiconductor production equipment. As shown in FIG. 1 of the accompanying drawings, the device includes wafer rollers 30 and 32 for rotating a wafer 50, a first brush 36 and a second brush 38 respectively disposed in order to contact with opposite surfaces of the wafer 50 and polishing each surface of the wafer 50 with received abrasives while contacting therewith when the wafer 50 rotates, a first jet nozzle 40 and a second jet nozzle 42 each disposed in order to supply and spray the abrasives between the first brush 36 and a surface of the wafer 50, and between the second brush 38 and the other surface of the wafer 50, and an idler 34 contacting with the wafer 50 disposed between the wafer rollers 30 and 32 and rotated by contact with the wafer 50.
However, the technique disclosed in Korean Patent Application Publication No. 10-2008-0109181 has an advantage that as the wafer 50 is rotated by the wafer rollers 30 and 32, the both surfaces of the wafer 50 are cleaned by the first brush 36 and the second brush 38, so particles of the both surfaces of the wafer are cleaned at the same time. However, the particles separated from the wafer 50 may enter the wafer rollers 30 and 32 such that the wafer slips, and the wafer 50 rotates abnormally due to hunting phenomenon in which the wafer 50 is ejected from the cleaner, so stable cleaning is impossible. In addition, when the particles enter between the wafer 50 and the idler 34, a rotation detecting device interlocking with the idler 34 cannot detect a rotation state of the wafer 50 exactly by slipping of the wafer 50 due to the particles, so an incomplete cleaning process cannot be detected.